Adsorption and Oxidative Desorption of Acetaldehyde
over Mesoporous Fe<i><sub>x</sub></i>O<i><sub>y</sub></i>H<i><sub>z</sub></i>/Al<sub>2</sub>O<sub>3</sub>

Published on 2019-03-15T13:46:23Z (GMT)
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Fe<i><sub>x</sub></i>O<i><sub>y</sub></i>H<i><sub>z</sub></i> nanostructures
were incorporated into commercially
available and highly porous alumina using the temperature-regulated
chemical vapor deposition method with ferrocene as an Fe precursor
and subsequent annealing. All processes were conducted under ambient
pressure conditions without using any high-vacuum equipment. The entire
internal micro- and mesopores of the Al<sub>2</sub>O<sub>3</sub> substrate
with a bead diameter of ∼2 mm were evenly decorated with Fe<i><sub>x</sub></i>O<i><sub>y</sub></i>H<i><sub>z</sub></i> nanoparticles. The Fe<i><sub>x</sub></i>O<i><sub>y</sub></i>H<i><sub>z</sub></i>/Al<sub>2</sub>O<sub>3</sub> structures showed substantially high activity
for acetaldehyde oxidation. Most importantly, Fe<i><sub>x</sub></i>O<i><sub>y</sub></i>H<i><sub>z</sub></i>/Al<sub>2</sub>O<sub>3</sub> with a high surface area (∼200
m<sup>2</sup>/g) and abundant mesopores was found to uptake a large
amount of acetaldehyde at room temperature, and subsequent thermal
regeneration of Fe<i><sub>x</sub></i>O<i><sub>y</sub></i>H<i><sub>z</sub></i>/Al<sub>2</sub>O<sub>3</sub> in air resulted in the emission of CO<sub>2</sub> with only a negligibly
small amount of acetaldehyde because Fe<i><sub>x</sub></i>O<i><sub>y</sub></i>H<i><sub>z</sub></i> nanoparticles
can catalyze total oxidation of adsorbed acetaldehyde during the thermal
treatment. Increase in the humidity of the atmosphere decreased the
amount of acetaldehyde adsorbed on the surface due to the competitive
adsorption of acetaldehyde and water molecules, although the adsorptive
removal of acetaldehyde and total oxidative regeneration were verified
under a broad range of humidity conditions (0–70%). Combinatory
use of room-temperature adsorption and catalytic oxidation of adsorbed
volatile organic compounds using Fe<i><sub>x</sub></i>O<i><sub>y</sub></i>H<i><sub>z</sub></i>/Al<sub>2</sub>O<sub>3</sub> can be of potential application in indoor and outdoor
pollution treatments.